Abstract

Recently there has been growing interest in optical dephasing (homogeneous linewidth) mechanisms in solids, both for scientific and technological¹ reasons. The role of spin flip-flops (SFF) in producing dephasing has long been recognized in nuclear and electron magnetic resonance, and these studies are now being extended to optical transitions. In particular direct proof of host nuclear SFF optical dephasing of unlike dopant nuclei has been achieved by the observation of magic- angle homogeneous line narrowing.² This work reports on a new technique for homogeneous line narrowing that demonstrates the existence of electronic SFF optical dephasing by like spins in ruby. The technique relies on selective depopulation of ground- state levels by R₂ optical pumping as well as on novel spin thermodynamics in the ground state produced by the strong dipolar coupling between electron spins.

© 1984 Optical Society of America